Various urethane resin compositions have been widely used as sealing agents, adhesive agents, and the like.
As such urethane resin compositions, use of one-part moisture-curable polyurethane composition, which cures by moisture in the air or the like, has been increasing recently from the perspective of ease in handling that does not require mixing and/or adjusting the composition on site when the composition is used, or the like.
For example, Japanese Unexamined Patent Application Publication No. 2000-128949A describes “a one-part moisture-curable polyurethane composition including: (A) a urethane prepolymer, and (B) a silane compound containing an average of at least 1.5 NCO groups and an average of at least 1.5 hydrolyzable alkoxy groups in each molecule, the silane compound containing at least one type selected from the group consisting of (B-1) a silane compound obtained by an addition reaction of a polyisocyanate compound having at least 3 NCO groups in each molecule and a secondary aminoalkoxysilane, wherein the polyisocyanate compound is a reaction product obtained by reacting a polyol that is a triol or higher polyol and that has a molecular weight of 500 or less with diisocyanate and (B-2) a silane compound that has a lysine backbone and that is obtained by an addition reaction of a lysine isocyanate having 2 or 3 isocyanate groups with a secondary aminoalkoxysilane” (Japanese Unexamined Patent Application Publication No. 2000-128949A).
However, it was found that, depending on the type of an adherend (coated plate), conventionally known one-part moisture-curable polyurethane compositions described in Japanese Unexamined Patent Application Publication No. 2000-128949A or the like may exhibit poor adhesion.